Cook the aromatics: Heat the oil in a large skillet over medium heat. Add the onion and a pinch of salt and cook for 4 to 5 minutes, until softened. Stir in the garlic and ginger and cook for about 1 minute, stirring often.
Toast the spices: Add the curry powder, cumin, turmeric, black pepper, red pepper flakes (if using) and tomato paste. Cook for 1 to 2 minutes, stirring constantly, until fragrant and slightly darkened.
Build the sauce: Pour in the coconut milk, soy sauce, sugar and broth (if using). Stir well, scraping up any browned bits from the bottom of the pan.
Simmer: Stir in the chickpeas, broccoli and bell peppers. Simmer for 7 to 8 minutes, or until the broccoli is tender and the peppers are softened but still slightly crisp.
Finish: Remove from the heat and stir in the spinach, lime juice and chopped cilantro. Stir until the spinach wilts. Taste and season with salt as needed.
Serve: Spoon over cooked rice and garnish with additional cilantro, lime wedges and roasted peanuts or cashews, if desired.